1. Field of the Invention
The present invention relates to a mounting apparatus for communication signal exchange equipment, and is particularly suitable for installing telephone exchange equipment.
2. Description of the Prior Art
In recent years, the demand for telephone sets has been increasing and, accordingly, it has been necessary to expand telephone networks. When the telephone networks are expanded, the number of subscriber lines are also increased. Consequently, a telephone exchange office has to deal with a large number of subscriber lines.
Originally telephone exchange equipment in a telephone exchange office was comprised of one mounting frame in which various kinds of electronic control units were contained. However, as the number of subscriber lines increased the telephone exchange equipment has had to be comprised of a plurality of mounting frames in each of which various kinds of electronic control units are contained. Since each of the electronic control units is relatively large and heavy, each of the mounting frames which contains many electronic control units is extremely large and heavy. Accordingly, it is difficult to transport a complete telephone exchange equipment comprised of a plurality of mounting frames from a manufacturing factory to the telephone exchange office.
In order to overcome the above mentioned difficulty, the following steps for installing the telephone exchange equipment have been provided. First, a plurality of mounting frames are produced in a manufacturing factory, in each of which mounting frames many cables are wired from one electronic control unit to another corresponding unit. Second, said plurality of mounting frames are transported from the factory to the telephone exchange office one by one, where frameworks which are located above the mounting frames and rigidly support said mounting frames have previously been constructed in the telephone exchange office. Third, each of the mounting frames is placed in a predetermined position in said office. Fourth, each of electronic control units of one mounting frame is electrically connected to a corresponding electronic control unit of another mounting frame by using a large number of cables.
The above mentioned four steps of the prior art have the following three defects. A first defect is that the length of time between the time when the mounting frames are placed in said office to the time when all of the electronic control units in said mounting frames can begin operation is extremely long. One reason for this is that the last step mentioned above cannot be started until all of the mounting frames have been placed in their predetermined positions in said office. Only when all of the mounting frames have been positioned can the cutting of each of said large number of cables to their desired length, the positioning of the end of each of the large number of cables at its desired position, and the distribution of each of the large number of cables through a predetermined path from one electronic control unit to another one be carried out. Another reason for the above mentioned first defect is that the cutting of the cables, the positioning of the ends of cables and the distribution of the cables is very time consuming and complicated. A second defect is that a transmission loss provided along each of the large number of cable becomes very large. This is because, since the distribution of all of the large number of cables from one component to other components is by way of overhead cable racks which are located above the components, the length of each of the cables becomes very long. A third defect is that, when the telephone exchange equipment is under construction, if it is necessary to connect some additional lead wires from some conductor pins of a printed circuit board in the electronic control unit to corresponding conductor pins of the connector of the same electronic control unit, the connection of said additional lead wires is not easily carried out.